Fiber reinforced composites provide increased performance over traditional materials, such as wood, in the areas of strength, durability and strength to weight ratio, but generally cannot provide as aesthetically pleasing surface appearances. Fiber reinforced composites typically have a solid colour surface which may be modified by painting etc. However, until now it has not been possible to provide a surface finish which has a detailed appearance.
Wood is a traditional material which provides a much more pleasant visual effect and as such it is desirable to have wood surfaces in a boat. However water craft are subject to relatively extreme weathering conditions from the combined action of sun, temperature, water and air etc. Whilst timber may be protected against weathering by use of suitable surface coatings, such coatings usually require periodic re-application or other maintenance to maintain the finish.
In the surfboard industry it is known to place small decals under the initial gel coat of fiber glass surfboards. These decals are a paper tissue onto which a design has been printed. When incorporated in a surfboard, the paper becomes transparent and leaves the design alone against whatever background colour has been selected.
Whilst use of small decals for a surfboard is practicable, it is not possible to "scale up" the technique for use on larger structures, such as a boat. The use of tissue paper in a fiber glass structure causes a discontinuity in the structure. Accordingly when subject to high loadings, the likelihood of the structure delaminating at the junction of the fiber glass and the paper is increased. The use of, for instance, a sheet of paper extending over a major portion of a composite would be unacceptable.
Tissue paper is generally inflexible and cannot be stretched. This is not a problem with surfboards where decals are placed on a generally planar surface. However where the surface is curved in more than one dimension, use of tissue paper is not practicable since this would require cutting of the paper to take out excess material and insertion of separate pieces in spaces. Obviously if a non-random design were utilised, this would result in an unacceptably distorted design, apart from the extra labour involved.
In an attempt to overcome the above problem the present invention, in one broadly form, provides a composite which includes at least one carrier layer of reinforcement bearing the design. Thus, in a glass fiber composite, the composite includes one or more layers of glass fiber upon which the design is carried.
Preferably the design is printed onto the filament or filaments of a single fiber layer. More preferably the layer is a non-woven layer. Use of a mono-filament non-woven fiber glass layer as the carrier for the design provides best results, but is not essential. Use of a woven mat will provide acceptable results especially with a simple design, such as a large logo. However use of woven matting near the surface of a composite generally causes "print-through", in which the gel coat, over time, adopts the surface profile of the underlying matting. Where an intricate design is used, this would generally not be acceptable. Use of woven matting also restricts the fine resolution one tries to effect in reproduction.
If desired an additional layer of reinforcement may be placed in front on the image carrying layer or layers. If this is done, a non-woven layer is best. Preferably no gel coat or additional reinforcement is placed in front of the design. Instead after the composite has cured multiple coats of a clear resin or varnish, such as a polyurethane resin, gives a deep rich lustre to the finished product. Use of such a resin or varnish also provides an excellent protective finish.
The design applied to the carrier may be of any form, such as company logo, photographic images or a graphical work.
When a photographic image is utilised, preferably it is manipulated electronically prior to application to the carrier. Whilst it is possible to transfer a photographic image to the carrier layer without manipulation, this generally results in dark areas being excessively dark and so lacking detail. Electronic manipulation to reduce the dynamic range of the lightest to the darkest areas produces more acceptable results.
If the image is repetitive, it is preferable to electronically "flip" the image end on end before application to the carrier layer. Such a manipulated image has no obvious joins within the single image. Further separate pieces of the carrier layer may be butted up to each other with mirror images on either side of the join. This enables a more "continuous" appearance to be obtained in which the joins are not readily visible.